I disassembled the mounting unit. The axle housing and the deck adjustment are all part of one piece of heavy formed iron. So there is no adjustment possible. What I did find however is that the caster wheel axle is slightly bent. I swapped with the other caster wheel and it rotates fine, although with minimal clearance of the deck adjustment appendage. So I am either going to straighten the axle out or purchase another one. The mower had to of taken a pretty hard hit to bend that axle I believe. Thanks Carscw for showing interest!